RECOMBINANT HUMAN BONE MORPHOGENETIC PROTEIN-2 FOR THE TREATMENT OF GUSTILO GRADE III OPEN TIBIA FRACTURES

Abstract

Open tibia fractures are often associated with delayed union and non-union. The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to treat acute, open tibial shaft fractures has been approved in both Europe (InductOs) and the United States (INFUSE Bone Graft). These approvals were based on the results of a prospective, randomized study of 450 patients with open tibia fractures that has already been published (Govender et al. 2002).

Material and Methods: A sub-group of patients from the above study with Gustilo Grade IIIA and IIIB open tibia fractures was separately analyzed. Patients treated with the standard of care (intramedullary nail fixation and routine soft-tissue management [the control group]) were compared to those that received the standard of care and an implant containing the approved concentration of rhBMP-2 (1.50 mg/mL). The primary outcome measured was the incidence of secondary intervention to promote bone healing during the twelve months of follow-up. Fischer’s exact test was used to compare the two groups.

Results: There were 55 patients in the control group and 59 patients in the rhBMP-2 group. The combined incidence of nail dynamization (those both performed and from broken screws) was higher in the control group 28/55 than the rhBMP-2 group 18/59. Significantly more control patients required autologous bone grafting because of delayed union or non-union as compared to the rhBMP-2 group [10/55 (18%) versus 1/59 (2%), respectively; p=0.0033]. More patients in the control group 15/55 required invasive secondary interventions to promote bone healing than those in the rhBMP-2 group 6/59 (p=0.0283). Fewer infections were observed in the rhBMP-2 group 14/59 as compared to the control group 23/55. In addition, the average time to full weight bearing for patients was 34 days sooner when rhBMP-2 was used (96 versus 130 days).

Conclusions: The addition of rhBMP-2 to the treatment of open tibia fractures represents a significant improvement over the standard of care. Treatment of Grade III tibia fractures with rhBMP-2 was shown to reduce the incidence of both invasive secondary interventions and infections. The additional expense of using rhBMP-2 can be justified for these severe fractures, by the potential to eliminate of the cost required to treat these complications.